In laser-based additive manufacturing (“LBAM”), a laser beam creates a weld pool into which powder is injected and melted. The substrate is scanned by the laser/powder system in order to trace a cross-section. Upon solidification, the trace forms a cross-section of a part. Consecutive layers are then additively deposited, thereby producing a three-dimensional component.
Sandia National Laboratories developed a technology known as Laser Engineering Net Shaping (“LENS”) to fabricate metal components directly from CAD solid models and thus further reduce the lead times for metal part fabrication. A similar process named Directed Light Fabrication (“DLF”) is under development at Los Alamos National Laboratory. The DLF process is more flexible because it has 5-axis positioning capability. This allows the manufacture more complex parts (i.e., overhangs) at the expense of increased cost and process planning complexity.
A variant of these two approaches is under development at the Fraunhofer Institute for Production Technology (“IPT”) named Controlled Metal Build Up (“CMB”). In this process the high-speed 2 1/2  axis CNC milling operation ensures that the required levels of form and dimensional accuracy, as well as of edge sharpness, are met. Numerous metallic materials ranging from bronze through steel to the hard alloys, frequently used to protect against wear, can be processed using this method. The fact that a high-speed milling operation takes place after each application of a new layer makes it possible to produce narrow deep grooves, since the engagement depth of the milling tool remains at a constant, low level. By virtue of the generative, layer-by-layer nature of this technique, the CAD data can be processed more quickly and with considerably less effort than is required for conventional 5-axis milling.